The present invention relates to an image processing apparatus for receiving image data from an image supply source, subjecting the image data to image processing and outputting the processed image data as output image data.
The images recorded on photographic films such as negatives and reversals (which are hereinafter referred to as xe2x80x9cfilmsxe2x80x9d) have been printed onto light-sensitive materials (photographic papers) by a technique generally called xe2x80x9cdirect exposurexe2x80x9d (analog exposure) in which the image on a film is projected onto the light-sensitive material for areal exposure.
In contrast, a printer which adopts digital exposure so called a digital photoprinter has been recently commercialized. In this digital photoprinter, the image recorded on a film is read photoelectrically; the thus read image is converted into digital signals; the digital signals are subjected to various kinds of image processing to produce the output image data for recording; and a light-sensitive material is scanned and exposed with recording light modulated in accordance with the image data, thereby an image (latent image) is recorded on the light-sensitive material and output as a (finished) print (photograph).
In digital photoprinters, the image is converted into digital image data and exposing conditions used in print operation can be determined by processing that image data. Hence, high quality prints which cannot be heretofore obtained by the conventional direct exposure can be obtained by preferably executing, by means of such digital photoprinters, a correction of washed-out highlight of images and dull shadow of images due to photography with backlight or an electronic flash, sharpness processing, a correction of color failure and density failure, a correction of under- or over-exposure, a correction of a insufficiency of marginal lumination, and various other kinds of image processing. In addition, a plurality of images can be composited into a single image or one image can be split into segments or even characters can be composited by the processing of image data. If desired, prints can be output after desired editing/processing is carried out in accordance with a specific application.
The capability of digital photoprinters is by no means limited to outputting the image as a print and they enable the image data to be supplied to computers and the like or stored in recording mediums such as floppy disks and so forth; thus, with digital photoprinters, the image data can be used in various applications other than photography.
Having these features, the digital photoprinter is composed of the following three basic components; a scanner (image reading apparatus) which photoelectrically reads the image recorded on a film; an image processing apparatus which subjects the read image data to image processing and outputs it as recording image data (exposure conditions); and a printer (image recording apparatus) which scans and exposes a light-sensitive material according to the image data and subjects the exposed light-sensitive material to development processing and outputs the light-sensitive material as prints.
In the scanner, the reading light issuing from a illuminant is allowed to be incident on the film, thereby producing projected light that carries the image recorded on the film; the projected light is then passed through an imaging lens to be focused on an image sensor such as a CCD sensor which performs photoelectric conversion to read the image, which is optionally subjected to various kinds of image processing before it is sent to the image processing apparatus as the image data (image data signals) from the film.
In the image processing apparatus, the image processing conditions are set on the basis of the image data which has been read with the scanner and image processing is performed on the image data in accordance with the thus set conditions, thereby producing output image data for image recording (i.e., exposing conditions) which are subsequently sent to the printer.
In the printer, if it is an apparatus which adopts exposure by scanning with optical beams, the optical beams are modulated in accordance with the image data supplied from the image processing apparatus, a latent image is formed by two-dimensionally scanning and exposing (printing) a light-sensitive material, and then the exposed light-sensitive material is subjected to predetermined development processing and the like so as to output a print on which the image which has been recorded on the film is reproduced.
Incidentally, images are recorded on a film under various conditions, and there are many cases in which a large difference exists between highlight images and shadow portion images (densities) as found in an image recorded with an electric flash or rear light, that is, there are many cases in which images have a greatly wide dynamic range.
When the images recorded on the film are exposed in an ordinary manner and prints are made therefrom, there is a case in which highlight images may be washed out and shadow images may be dulled. For example, when a person is photographed with rear light, if exposure is executed so that the person is reproduced as a preferable image, a highlight image such as a sky is washed out to white, in contrast if the exposure is executed so that the sky is reproduced as a preferable image, the person is dulled.
To cope with this problem, when a light-sensitive material is exposed using a film image, which has a large difference between highlight images and shadow images, as an original, a method referred to as so-called dodging is employed.
Dodging is a technique for obtaining a print on which appropriate images, which are near to an impression a person gets when he or she observes an original scene, are reproduced over the entire image of the print by correcting the large difference between the highlight images and the shadow images of the images recorded on the film. Dodging processing is carried out by ordinarily exposing the portion having an intermediate density, exposing the highlight portion, in which images are liable to be washed out, with an increased quantity of light (exposure) and exposing the shadow portion, in which images are liable to be dulled, with a reduced quantity of light (exposure).
In the conventional apparatus employing the direct exposure, the dodging processing has been carried out by a method of executing exposure by inserting a shading plate, an ND filter or the like into an exposure light path; a method of partly changing the quantity of light of an exposure light source; a method of making a monochrome film in which the highlight portion and the shadow portion of the images recorded on a film are reversed and executing exposure in the state that the monochrome film is placed on the above film, and the like, so that the quantity of exposure light is partly changed in accordance with the images recorded on the film.
Whereas, in the digital photoprinter, the dodging processing is carried out by compressing the dynamic range of images in image data processing so that highlight images and shadow images can be preferably reproduced, whereby images, which are near to an impression of when a person observes an original scene, can be reproduced. That is, an image histogram of image data is created over the entire images and the washed-out images of the highlight portions and the dull images of the shadow portions are removed by compressing a low frequency component to thereby realize an abundant gradation representation of the images.
When it is intended to correct the gradation of, for example, a wedding dress which is liable to be washed out in analog exposure, an operator conventionally prevents the occurrence of the washing-out to white by dodging or strongly printing only the region of the wedding dress. In this method, however, there is a problem that the operator is required to have a skilled technique and a job is very troublesome.
Further, digital exposure also has a problem that it is impossible to apply the dodging processing only to a particular region of images and to control the gradation of only the region, although it is possible, in the dodging processing which is applied to the entire images described above, to create an image histogram and to set optimum conditions such as the compression of a highlight side dynamic range, the compression of a shadow side dynamic range and the like for each image.
Intrinsically, a region where it is desired to apply the dodging processing is different depending upon, for example, a scene, the intention of a photographer, and the sensitivity of the operator who finishes a photograph.
Fairly satisfactorily finished prints can be obtained in the field of amateur photographs by the dodging processing applied to entire images. However, the dodging processing applied to the entire image is not always sufficient in the photographic field of professionals and so-called xe2x80x9cadvanced amateursxe2x80x9d who are particularly interested in finishing conditions.
An object of the present invention, which was made in view of the above conventional problems, is to provide an image processing apparatus which has a mode for applying dodging processing to entire images, a mode for applying the dodging processing only to a designated region, a mode for applying the dodging processing to a designated region and to the regions other than the designated region in different intensity, and the like and which can carry out the dodging processing to the entire images, only to the designated region or only to the designated region in the different intensity after the apparatus interactively designates the region to which the dodging processing is applied or the region to which the dodging processing is applied in the different intensity by optionally or automatically switching the above modes.
In order to attain the above-described object, the first aspect of the present invention provides an image processing apparatus for receiving image data from an image data supply source and converting the image data into output image data by subjecting the image data to image processing, comprises:
first dodging processing means for applying automatic dodging processing to an entire image of one frame;
means for interactively instructing a region from an image of said one frame; and
second dodging processing means for applying the automatic dodging processing only to the instructed region.
In the first aspect, it is preferable that said first dodging processing means applies said automatic dodging processing in uniform intensity.
It is also preferable that the image processing apparatus includes, as an automatic dodging processing mode, a mode in which the automatic dodging processing is applied to the entire images by said first dodging processing means and a mode in which the automatic dodging processing is applied only to the instructed region by said second dodging processing means, the mode in which the automatic dodging processing is applied to the entire images is set as a basic mode, and the image processing apparatus further comprises switching means for switching the modes from the basic mode to the mode in which the automatic dodging processing is applied only to the instructed region.
It is further preferable that the automatic dodging processing compresses a dynamic range of the image by compressing a low frequency component of the image data of a region to be processed and said first and second dodging processing means have means for compressing the low frequency component commonly used in both of said first and second dodging processing means.
It is also further preferable that said first dodging processing means has first compressing means for compressing a low frequency component of the image data of the entire image to apply the automatic dodging processing, second dodging processing means has second compressing means for compressing the low frequency component by weighting the low frequency component with an signal for instructing the region due to said instructing means and said first and second compressing means are commonly used.
It is still further preferable that an signal for instructing the regions can be input externally by said instructing means.
The second aspect of the resent invention provides an image processing apparatus for receiving image data from an image data supply source and converting the image data into output image data by subjecting the image data to image processing, comprising:
first dodging processing means for applying automatic dodging processing to an entire image of one frame;
means for interactively instructing a region from an image of said one frame; and
third dodging processing means for applying the automatic dodging processing to the instructed region and to the regions other than the instructed region in different intensity.
In the second aspect, it is preferable that said first dodging processing means applies said automatic dodging processing in uniform intensity.
It is also preferable that the image processing apparatus includes, as an automatic dodging mode, a mode in which the automatic dodging processing is applied to the entire images in uniform intensity by said first dodging processing means and a mode in which the automatic dodging processing is applied to the instructed region and to the regions other than the instructed region in different intensity by said third dodging processing means, the mode in which the automatic dodging processing is applied to the entire images is set as a basic mode, and the image processing apparatus further comprises switching means for executing switching from the basic mode to the mode in which the dodging processing is applied to the instructed region and to the regions other than the instructed region in different intensity.
It is further preferable that the automatic dodging processing compresses a dynamic range of the image by compressing a low frequency component of the image data of a region to be processed and said first and third dodging processing means have means for compressing the low frequency component commonly used in both of said first and third dodging processing means.
It is still further preferable that an signal for instructing the regions can be input externally by said instructing means.
The third aspect of the present invention provides an image processing apparatus for receiving image data from an image data supply source and converting the image data into output image data by subjecting the image data to image processing, comprising:
first dodging processing means for applying automatic dodging processing to an entire image of one frame;
means for interactively instructing a region from an image of said one frame;
second dodging processing means for applying the automatic dodging processing only to the instructed region; and
third dodging processing means for applying the automatic dodging processing to the instructed region and to the regions other than the instructed region in different intensity.
In the third aspect, it is preferable that said first dodging processing means applies said automatic dodging processing in uniform intensity.
It is also preferable that the image processing apparatus includes, as an automatic dodging processing mode, a mode in which the automatic dodging processing is applied to the entire image in uniform intensity by said first dodging processing means, a mode in which the automatic dodging processing is applied only to the instructed region by said second dodging processing means and a mode in which the automatic dodging processing is applied to the instructed region and to the regions other than the instructed region in different intensity by said third dodging processing means, the mode in which the automatic dodging processing is applied to the entire image is set as a basic mode, and the image processing apparatus further comprises switching means for switching the modes from the basic mode to any of the mode in which the automatic dodging processing is applied only to the instructed region and the mode in which the automatic dodging processing is applied to the instructed region and to the regions other than the instructed region in different intensity.
It is further preferable that the automatic dodging processing compresses a dynamic range of the image by compressing a low frequency component of the image data of a region to be processed and said first, second and third dodging processing means have means for compressing the low frequency component is commonly used in said first, second and third dodging processing means.
It is still further preferable that wherein an signal for instructing the regions can be input externally by said instructing means.